Paper bulking promoter

ABSTRACT

This invention is to provide a paper bulking promoter with which a highly bulky sheet can be obtained without impairing paper strength. Namely, this invention provides a process for producing a bulky paper, comprising the step of making paper from pulp in the presence of a bulking promoter comprising a cationic compound.

BACKGROUND OF THE PRIOR ART

[0001] 1. Technical Field

[0002] This invention relates to a paper bulking promoter with which thesheets of paper obtained from a pulp feedstock can be bulky withoutimpairing paper strength.

[0003] 2. Description of the Prior Art

[0004] Recently, there is a desire for high-quality paper, e.g., paperexcellent in printability and voluminousness. Since the printability andvoluminousness of paper are closely related to the bulkiness thereof,various attempts have been made to improve bulkiness. Examples of suchattempts include a method in which a crosslinked pulp is used (JP-A4-185792, etc.) and a method in which a mixture of pulp with syntheticfibers is used as a feedstock for papermaking (JP-A 3-269199, etc.).Examples thereof further include a method in which spaces among pulpfibers are filled with a filler such as an inorganic (JP-A 3-124895,etc.) and a method in which spaces are formed (JP-A 5-230798, etc.). Onthe other hand, with respect to mechanical improvements, there is areport on an improvement in calendering, which comprises conductingcalendering under milder conditions (JP-A 4-370298).

[0005] However, the use of a crosslinked pulp, synthetic fibers, etc.makes pulp recycling impossible, while the technique of merely fillingpulp fiber spaces with a filler and the technique of forming spacesresult in a considerable decrease in paper strength. Furthermore, theimprovement in mechanical treatment produces only a limited effect andno satisfactory product has been obtained so far.

[0006] Also known is a method in which a bulking promoter is addedduring papermaking to impart bulkiness to the paper. Although fatty acidpolyamide polyamines for use as such bulking promoters are on themarket, use of these compounds results in a decrease in paper strengthand no satisfactory performance has been obtained therewith.

SUMMARY OF THE INVENTION

[0007] The inventors have made intensive investigations in view of theproblems described above. As a result, they have found that byincorporating at least one compound selected among specific cationiccompounds, amine compounds, acid salts of amine compounds, amphotericcompounds, amide compounds, quaternary ammonium salts, and imidazolinederivatives optionally together with at least one specific nonionicsurfactant into a pulp feedstock, e.g., a pulp slurry, in thepapermakinq step, the sheet made from the feedstock can have improvedbulkiness without detriment to paper strength. This invention has thusbeen achieved.

[0008] Namely, this invention provides a process for producing a bulkypaper, comprising the step of making paper from pulp in the presence ofa bulking promoter comprising at least one compound selected from thegroup consisting of a cationic compound, an amine compound, an acid saltof an amine compound, an amphoteric compound, an amide compound, aquaternary ammonium salt, and an imidazoline derivative.

[0009] The term “paper bulking promoter” used herein means an agent withwhich a sheet of paper obtained from a pulp feedstock can have a largerthickness (can be bulkier) than that having the same basis weightobtained from the same amount of a pulp feedstock.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0010] Examples of the cationic compounds for use in this inventioninclude compounds represented by the following formulae (a₁) and (b₁):

[0011] wherein R₁₁ and R₁₂ are the same as or different from each other,and an alkyl, alkenyl or β-hydroxyalkyl group having 8 to 24 carbonatoms; R₁₃, R₁₄ and R₁₅ are the same as or different from each other,and an alkyl or hydroxyalkyl group having 1 to 8 carbon atoms, benzyl or—(AO)n₁₁—Z₁₁, wherein AO is an oxyalkylene unit having 2 or 3 carbonatoms, Z₁₁ is a hydrogen atom or an acyl group and n₁₁ is an integer of1 to 50; R₁₆ is an alkyl, alkenyl or β-hydroxyalkyl group having 8 to 36carbon atoms; and X⁻ is an anionic ion.

[0012] In the formula (a₁), R₁₁ and R₁₂, which are the same ordifferent, each preferably is an alkyl or alkenyl group having 10 to 22carbon atoms. R₁₃ and R₁₄, which are the same or different, eachpreferably is a hydrogen atom or an alkyl group having 1 to 3 carbonatoms. Examples of X⁻, which is an anionic ion, include hydroxy, halide,and monoalkyl (C1-C3) sulfate ions and anions derived from inorganic ororganic acids. X⁻ is preferably a halide ion, especially Cl⁻.

[0013] In the formula (b₁), R₁₃, R₁₄, and R₁₅, which are the same ordifferent, each is preferably an alkyl group having 1 to 3 carbon atomsor a benzyl group. R₁₆ is preferably an alkyl group having 10 to 22carbon atoms. Examples of the anionic ion X⁻ are the same as those inthe formula (a₁). X⁻ is preferably a halide ion, especially Cl⁻.

[0014] In the present invention, the cationic compounds may includequaternary ammonium salts.

[0015] Hereinafter X may be an anionic ion as an anionic ion.

[0016] Examples of the amine compounds and the acid salts of aminecompounds for use in this invention include compounds represented by thefollowing formulae (a₂) to (f₂):

[0017] wherein R₂₁ is an alkyl, alkenyl or β-hydroxyalkyl group having 8to 36 carbon atoms; R₂₂ and R₂₃ are the same as or different from eachother, and a hydrogen atom, an alkyl group having 1 to 24 carbon atomsor an alkenyl group having 2 to 24 carbon atoms; R₂₄ and R₂₅ are thesame as or different from each other, and a hydrogen atom or an alkylgroup having 1 to 3 carbon atoms; HB represents an inorganic acid or anorganic acid; AO is an oxyalkylene unit having 2 or 3 carbon atoms; l₂₁and m₂₁ are 0 or a positive integer, and the sum in total of l₂₁, andm₂₁ is in an integer ranging from 1 to 300; and n₂₁ is a number of 1 to4.

[0018] In the formulae (a₂) to (f₂), R₂₁ is preferably an alkyl grouphaving 10 to 22 carbon atoms. R₂₂ and R₂₃, which are the same ordifferent, each preferably is a hydrogen atom or an alkyl group having 1to 22 carbon atoms. In HB in the acid salts of amine compounds, B ispreferably a halogen or a carboxylate having 2 to 5 carbon atoms,especially preferably a carboxylate having 2 or 3 carbon atoms.Preferred amine compounds and preferred acid salts of amine compoundsare the compounds represented by the formulae (a₂) and (b₂),respectively.

[0019] The acid salt represented by the formula (b₂) may be signified bythe following formula (b₂₁):

[0020] wherein R₂₁, R₂₂ and R₂₃ are same as above-mentioned; H ishydrogen atom; and B represents a base.

[0021] That is, the acid salt may be an ionized compound.

[0022] Examples of the amphoteric compounds for use in this inventioninclude compounds represented by the following formulae (a₃) to (j₃):

[0023] wherein R₃₁, R₃₂ and R₃₃ are the same as or different from eachother, and an alkyl group having 1 to 24 carbon atoms or an alkenylgroup having 2 to 24 carbon atoms; R₃₄ is an alkyl, alkenyl orβ-hydroxyalkyl group having 8 to 36 carbon atoms; M is a hydrogen atom,an alkali metal atom, a half a mole of an alkaline earth metal atom oran ammonium group; Y₃₁ is R₃₅NHCH₂CH₂—, wherein R₃₅ is an alkyl grouphaving 1 to 36 carbon atoms, or an alkenyl or a hydroxy alkyl grouphaving 2 to 36 carbon atoms; Y₃₂ is a hydrogen atom or R₃₅NHCH₂CH₂—, R₃₅being defined above; Z₃₁ is —CH₂COOM, M being defined above; and Z₃₂ isa hydrogen atom or —CH₂COOM, M being defined above.

[0024] In the formulae (a₃) to (j₃), R₃₁, R₃₂, and R₃₃, which are thesame or different, each preferably is an alkyl group having 1 to 22carbon atoms. Especially preferably, R₃₁ is an alkyl group having 10 to20 carbon atoms, and R₃₂ and R₃₃ each is an alkyl group having 1 to 3carbon atoms. R₃₄ is preferably an alkyl group having 10 to 22 carbonatoms. Preferred amphoteric compounds are those represented by theformulae (a₃) and (b₃).

[0025] Examples of the other amine compounds and the other acid salts ofan amine compound for use in this invention include compoundsrepresented by the following formulae (a₄) to (d₄):

[0026] wherein R₄₁ is an alkyl, alkenyl or β-hydroxyalkyl having 8 to 35carbon atoms; R₄₃ and R₄₄ are same as or different from each other, analkyl, alkenyl or β-hydroxyalkyl group having 7 to 35 carbons atoms; R₄₆is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; R₄₅ isan alkyl group having 1 to 3 carbon atoms; R₄₂ is a hydrogen atom orR₄₇, wherein R₄₇ is an alkyl, alkenyl or β-hydroxyalkyl group having 7to 35 carbons atoms; Y₄₁ is a hydrogen or —COR₄₄; and Z₄₁ is—CH₂CH₂O(AO)n₄₁—OCOR₄₇, wherein A is a liner or branched alkylene unithaving 2 to 3 carbon atoms, or —CH₂CH(OH)—CH₂OCOR₄₇ and n₄₁ is anaverage added-number ranging 1 to 20.

[0027] Examples of the amide compounds for use in this invention includecompounds represented by the following formulae (a₅) and (b₅):

[0028] wherein R₅₁ and R₅₄ are same as or different from each other, analkyl, alkenyl or β-hydroxyalkyl group having 7 to 35 carbon atoms; R₅₂and R₅₃ are same as or different from each other, a hydrogen atom or analkyl group having 1 to 3 carbon atoms; and Y₅₁ and Y₅₂ are same as ordifferent from each other, and a hydrogen atom, R₅₂CO—, R₅₄CO—,—(AO)n₅₁—COR₅₅, wherein A is a liner or branched alkylene unit having 2to 3 carbon atoms n₅₁ is an average added-number ranging 1 to 20, andR₅₅ is an alkyl, alkenyl or β-hydroxyalkyl group having 7 to 35 carbonatoms, or —(AO)n₅₁—H, wherein A and n₅₁ are defined above.

[0029] Examples of the cationic compounds for use in this inventioninclude quaternary ammonium salts represented by the following formulae(a₆) and (b₆):

[0030] wherein R₆₁ and R₆₃ are same as or different from each other, analkyl, alkenyl or β-hydroxyalkyl group having 7 to 35 carbons atoms; R₆₅is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; R₆₂ andR₆₄ are same as or different from each other, an alkyl group having 1 to3 carbon atoms; and X⁻ is an anionic ion.

[0031] Examples of the imidazoline derivative for use in this inventioninclude compounds represented by the following formulae (a₇):

[0032] wherein R₇₁ is an alkyl, alkenyl or β-hydroxyalkyl group having 7to 35 carbons atoms.

[0033] The paper bulking promoter of this invention preferably furthercontains at least one specific nonionic surfactant. By the use of atleast one of compounds represented by the above formulae (a₁) and (b₁),(a₂) to (e₂), (a₃) to (h₃), (a₄) to (d₄), (a₅) and (b₅), (a₆) and (b₆),and (a₇); and at least one specific nonionic surfactant in combination,the effect of this invention can be improved. Examples of the nonionicsurfactant for use in this invention include the following (A) to (C).

[0034] (A): a compound represented by the following formula (A)

R₈₁O (EO)_(m) ₈₁ (PO)_(n) ₈₁ H  (A)

[0035] wherein R₈₁ is a C6 to C22 straight or branched alkyl or alkenylgroup or an alkylaryl group having a C4 to C20 alkyl group; E is anethylene unit; P is a propylene unit; m₈₁ and n₈₁ are an average numberof added moles, m₈₁ is a number in the range of 0 to 20 and n₈₁ is anumber in the range of 0 to 50; and the addition form of EO and PO maybe any of block and random and the addition order of EO and PO may benot limited.

[0036] The compounds represented by the formula (A) are ones eachobtained by causing a higher alcohol, an alkylphenol, or the like inwhich the alkyl has 6 to 22 carbon atoms to add an alkylene oxide suchas ethylene oxide (EO) or propylene oxide (PO). In this invention isused the compound in which the average number of moles of ethylene oxideadded is in the range of 0≦m₈₁≦20. The range of the average number ofmoles added, m₈₁, is preferably 0≦m₈₁≦10, more preferably 0≦m₈₁≦5. Ifm₈₁ exceeds 20, the effect of imparting bulkiness to paper is lessened.Further, the compound used is one in which the average number of molesof propylene oxide (PO) added, n₈₁, is in the range of 0≦n₈₁≦50,preferably 0≦n₈₁≦20. When n₈₁ exceeds 50, such a compound iseconomically disadvantageous although the decrease in performance islittle.

[0037] R₈₁ in the formula (A) is preferably a linear or branched, alkylor alkenyl group having 8 to 18 carbon atoms. If R₈₁ in the formula (A)is an alkyl or alkenyl group in which the number of carbon atoms isoutside the range of from 6 to 22 or if R₈₁ is an alkylaryl group inwhich the number of carbon atoms of the alkyl group is outside the rangeof from 4 to 20, then the compound is less effective in impartingbulkiness to paper.

[0038] Examples of E and P in the formula (A), which each represents alinear or branched alkylene group having 2 or 3 carbon atoms, includeethylene and propylene. When the group (EO)_(m) ₈₁ (PO)_(n) ₈₁ in theformula (A) is composed of a combination of polyoxyethylene andpolyoxypropylene, the C₂H₄O and C₃H₆O units may have any of random andblock arrangements (, or the addition form of EO and PO may be any ofblock and random). In this case, the polyoxypropylene (C₃H₆O) group(s)account for preferably at least 50 mol %, especially preferably at least70 mol %, of all groups added on the average. The alkylene oxide groupbonded to R may begin with any of EO and PO (, or the addition order ofEO and PO may be not limited).

[0039] (B): Compounds represented by the following formula (B)

R₈₁COO (EO)_(m) ₈₁ (PO)_(n) ₈₁ R_(b)  (B)

[0040] wherein R₈₁, E, P, m₈₁ and n₈₁ are the same as those of theformula (A) ; and R_(b) is H, an alkyl, an alkenyl or an alkylarylgroup.

[0041] Preferred examples of R₈₁, E, P, m₈₁, and n₈₁ in the formula (B)are the same as those in the formula (A). Examples of the alkyl andalkenyl groups represented by R_(b) in the formula (B) include thosehaving 1 to 4 carbon atoms, while examples of the alkylaryl grouprepresented by R_(b) include alkylphenyl groups in each of which thealkyl has 1 to 4 carbon atoms.

[0042] (C): a nonionic surfactant selected from the followings (1) to(3):

[0043] (1) an oil-fat type nonionic surfactant (i.e. a ninionicsurfactant based on fat),

[0044] (2) a sugar-alcohol type nonionic surfactant (i.e. a nonionicsurfactant based on sugar alcohol) and

[0045] (3) a sugar-type nonionic surfactant (1.e. a nonionic surfactantbased on sugar).

[0046] (1) Nonionic Surfactants Based on Fat

[0047] Examples of the nonionic surfactants based on a fat (1) includeones obtained by mixing an alcohol having 1 to 14 hydroxy groups with afat such as those given in, e.g., JP-A 4-352891 or with a product of thereaction of the fat with glycerol and causing the mixture to add analkylene oxide (AO) Preferred is one obtained by causing a mixture of afat and a polyhydric alcohol to add an AO. The AO is ethylene oxide (EO)and/or propylene oxide (PO). In the case of using both EO and PO, theEO/PO polymer may have any of random and block arrangements. The averagenumber of moles of EO added is preferably 0 to 200, more preferably 10to 100, while that of PO added is preferably 0 to 150, more preferably 2to 100.

[0048] Examples of the fat usable for this type of nonionic surfactantinclude land animal fats, marine animal fats, hardened or semihardenedoils obtained therefrom, and recovery oils obtained during thepurification of these fats. Preferred examples thereof include coconutoil, beef tallow, fish oils, linseed oil, rapeseed oil, and castor oil.In the case where any of these fats is reacted beforehand with glycerol,the fat/glycerol ratio is preferably from 1/0.05 to 1/1.

[0049] Examples of monohydric alcohols among the alcohols having 1 to 14hydroxy groups usable for this type of nonionic surfactant includelinear or branched, saturated or unsaturated alcohols having 1 to 24carbon atoms and cyclic alcohols. Preferred are linear or branched,saturated alcohols having 4 to 12 carbon atoms. Examples of dihydricalcohols include α,ω-glycols having 2 to 32 carbon atoms, 1,2-diols,symmetric α-glycols, and cyclic 1,2-diols. Preferred are α,ω-glycolshaving 2 to 6 carbon atoms. Examples of trihydric and higher alcoholsinclude those having 3 to 24 carbon atoms, such as glycerol, diglycerol,sorbitol, and stachyose. Especially preferred alcohols are di- tohexahydric alcohols having 2 to 6 carbon atoms.

[0050] (2) Nonionic Surfactants Based on Sugar Alcohol

[0051] Examples of the nonionic surfactants based on a sugar alcohol (2)include sugar alcohol/AO adducts, fatty acid esters of sugar alcohol/AOaddicts, and fatty acid esters of sugar alcohols. The sugar alcohol as acomponent of a nonionic surfactant based on a polyhydric alcohol is analcohol obtained from a monosaccharide having 3 to 6 carbon atomsthrough reduction of the aldehyde or ketone group. Examples thereofinclude glycerol, erythritol, arabitol, sorbitol, and mannitol.Especially preferred are those having 6 carbon atoms. The fatty acid asa component of the fatty acid ester in a sugar alcohol/AO adduct may beany of saturated and unsaturated fatty acids each having 1 to 24,preferably 12 to 18, carbon atoms. Preferred is oleic acid. With respectto the degree of esterification of the sugar alcohol, the number of OHgroups which have undergone esterification may be any of from zero toall of the OH groups. However, the degree of esterification ispreferably 1 to 3. The kinds of AO and the average number of moles of AOadded are the same as in (1).

[0052] (3) Nonionic Surfactants Based on Sugar

[0053] Examples of the nonionic surfactants based on a sugar (3) includesugar/AO adducts, fatty acid esters of sugar/AO adducts, and sugar/fattyacid esters. The sugar may be a polysaccharide such as sucrose, besidesany of the monosaccharides mentioned above with regard to the sugaralcohol. Preferred are glucose and sucrose. The kinds of AO and theaverage number of moles of AO added are the same as in (1) . Especiallypreferred of the nonionic surfactants based on a sugar (3) are sugar/AOadducts, in particular, glucose/PO adducts in which the average numberof moles of PO added is 1 to 10.

[0054] When at least one compound (i) selected among cationic compounds,amine compounds, acid salts of amine compounds, amphoteric compounds,amide compounds, quaternary ammonium salts, and imidazoline derivativesis used in combination with at least one nonionic surfactant (ii) suchas the compounds (A) to (C) described above, the proportion of thecompound (i) to the nonionic surfactant (ii) is from 100/0 to 1/99,preferably from 100/0 to 10/90 by weight.

[0055] The compounds (i) and (ii) maybe added either as a mixture ofboth or separately.

[0056] The bulking promoter of this invention is applicable to a varietyof ordinary pulp feedstocks ranging from virgin pulps such as mechanicalpulps and chemical pulps to pulps prepared (deinked) from various wastepapers. The point where the bulking promoter of this invention is addedis not particularly limited as long as it is within the papermakingprocess steps. In a factory, for example, the bulking promoter isdesirably added at a point where it can be evenly blended with a pulpfeedstock, such as, the refiner, machine chest, or headbox. After thebulking promoter of this invention is added to a pulp feedstock, theresultant mixture is subjected as it is to sheet forming. The bulkingpromoter remains in the paper. The paper bulking promoter of thisinvention is added in an amount of 0.01 to 10 wt. %, preferably 0.1 to 5wt. %, based on the pulp.

[0057] The pulp sheet obtained by using the paper bulking promoter ofthis invention has a bulk density (the measurement method is shown inthe Examples given later) lower by desirably at least 5%, preferably atleast 7% than the product not containing the paper bulking promoter andhas a tearing strength as measured according to JIS P 8116 of desirablyat least 90%, preferably at least 95% of that of the product.

EXAMPLES

[0058] This invention will be explained below in more detail byreference to Examples, but the invention should not be construed asbeing limited thereto. In the Examples, all parts and percents are basedon weight unless otherwise indicated.

[0059] When the unit number of an (AO) group is, defined by an integer,the compound is one of a mixture of reaction products. When it isdefined by an average value, the compound is a mixture of reactionproducts.

Examples 1 to 42 and Comparative Example 1

[0060] [Pulp Feedstocks]

[0061] The deinked pulp and virgin pulp shown below were used as pulpfeedstocks.

[0062] <Deinked Pulp>

[0063] A deinked pulp was obtained in the following manner. To feedstockwaste papers collected in the city (newspaper/leaflet=70/30%) were addedwarm water, 1% (based on the feedstock) of sodium hydroxide, 3% (basedon the feedstock) of sodium silicate, 3% (based on the feedstock) of a30% aqueous hydrogen peroxide solution, and 0.3% (based on thefeedstock) of EO/PO block adduct of beef tallow/glycerol (1:1), as adeinking agent, in which the amounts of EO and PO were respectively 70and 10 (average number of moles added). The feedstock was disintegratedand then subjected to flotation. The resultant slurry was washed withwater and regulated to a concentration of 1% to prepare a deinked pulp(DIP) slurry. This DIP had a freeness of 220 ml.

[0064] <Virgin Pulp>

[0065] A virgin pulp was prepared by disintegrating and beating an LBKP(bleached hardwood pulp) with a beater at room temperature to give a 1%LBKP slurry. This LBKP had a freeness of 420 ml.

[0066] [Bulking Promoters]

[0067] The cationic compounds, amine compounds, acids salts of aminecompounds, and amphoteric compounds shown in Tables 1 to 5 were usedoptionally together with the nonionic surfactants shown in Table 6 inthe combinations shown in Tables 7 and 8, which will be given later.TABLE 1 Compound Structure in the formula (a1) No. R₁₁ R₁₂ R₁₃ R₁₄ X⁻Cationic Compound A-1 C18 C18 C1 C1 Cl⁻ A-2 C12 C14 C1 C1 Cl⁻ a-1 C2 C2  C1 C1 Cl⁻ a-2 C4  C4  C1 C1 Br⁻

[0068] TABLE 2 Compound Structure in the formula (b1) No. R₁₃ R₁₄ R₁₅R₁₆ X⁻ Cationic Compound B-1 C1 C1 C1 C12 Cl⁻ B-2 C1 C1 C1 C16 Br⁻ B-3C1 C1 C1 C18 Cl⁻ B-4 benzyl C1 C1 C12 Cl⁻ b-1 C1 C1 C1 C2  Cl⁻ b-2 C1 C1C1 C4  Br⁻

[0069] TABLE 3 Compound Structure in the formula (a2) or (b₂) No. R₂₁R₂₂ R₂₃ HB Amine compound and acid salt of amine compound C-1 C12 H H —C-2 C18 H H — C-3 C16/C18 = C16/C18 = H — 3/7 3/7 C-4 C18 C1 C1 — c-1C4  H H — c-2 C6  H H — c-3 C2  C2 H — c-4 C4  C1 C1 — C-5 C16/C18 = H HCH₃COOH 3/7 c-5 C4  H H CH₃COOH

[0070] TABLE 4 Structure in the Compound formula (a₃) No. R₃₁ R₃₂ R₃₃Amphoteric compound D-1 C12 C1 C1 d-1 C4  C1 C1

[0071] TABLE 5 Structure in the formula Compound (b₃) No. R₃₁ R₃₂ R₃₃Amphoteric compound D-2 C12 C1 C1 D-3 C18 C1 C1 d-2 C6  C1 C1

[0072] TABLE 6 (1)/(2)/(3) Nonionic surfactant Weight No. (1) (2) (3)ratio 1 C12 alcohol 100/0/0 2 C12/C14 alcohol = 5/5 100/0/0 PO = 5 3Beef tallow/fatty acid, 100/0/0 PO = 5 4 Methyl laurate, 100/0/0 EO2/PO3block 5 Coconut 100/0/0 oil/glycerol = 1/1, EO2/PO10 block 6 Sorbitanmonooleate, 100/0/0 EO20 7 Dobanol23 EO2/PO4 Sorbitan 75/25/0  randommonooleate, EO10 8 C12 alcohol Sorbitan Hardened 80/15/5  monooleate,EO15 castor oil, EO25 9 C18 alcohol, PO = 10 100/0/0 10 Castor oil/fattyacid, 100/0/0 EO5/PO15 random 11 C12/C14/C18 C12 alcohol EO = 5 Fishoil/ 75/15/10 alcohol = 6/2/2, PO = 10 sorbitol = 1/1, PO = 15 12 Beeftallow/glycerol = 100/0/0 1/0.3 EO10/PO10 block 13 Sorbitan monolaurate,100/0/0 EO15 14 C12/C14/C18 lauric acid EO5, 90/10/0  alcohol =60/30/10, PO25 PO20 15 C12/C14 alcohol = 70/30 100/0/0 16 Lauricacid/stearic 100/0/0 acid = 50/50, PO = 18 17 Dobanol23, PO = 2 lauricacid/myristic Sorbitan 70/15/15 acid/palmitic acid = trioleate EO670/20/10. EO10, PO20

[0073] (Note) In the table, Cn means an alkyl group having n carbonatoms. In Table 6, each fat/polyhydric alcohol ratio is by mole, and theother ratios are by weight. EO and PO mean ethylene oxide and propyleneoxide, respectively, and the numbers following these are the averagenumbers of moles added. “Dobanol 23” is an alcohol manufactured byMitsubishi Chemical.

[0074] [Papermaking Method]

[0075] Each of the above 1% pulp slurries was weighed out in such anamount as to result in a sheet of paper having a basis weight of 60g/m². The pH thereof was adjusted to 4.5 with aluminum sulfate.Subsequently, various bulking promoters shown in Tables 7 and 8 wereadded in an amount of 3% based on the pulp. Each resultant mixture wasformed into a sheet with a rectangular TAPPI paper machine using an80-mesh wire. The sheet obtained was pressed with a press at 3.5 kg/cm²for 2 minutes and dried with a drum dryer at 105° C. for 1 minute. Aftereach dried sheet was held under the conditions of 20° C. and a humidityof 65% for 1 day to regulate its moisture content, it was evaluated forbulk density as a measure of paper bulkiness and for tearing strength asa measure of paper strength performance. The results obtained are shownin Tables 7 and 8. Ten found values were averaged.

[0076] <Evaluation Item and Method>

[0077] Bulkiness (bulk density)

[0078] The basis weight (g/m²) and thickness (mm) of each sheet having aregulated moisture content were measured, and its bulk density (g/cm³)was determined as a calculated value.

[0079] Equation for calculation:

Bulkiness (Bulk Density)=(basis weight)/(thickness)×0.001

[0080] The smaller the absolute value of bulk density, the higher thebulkiness. A difference of 0.02 in bulk density is sufficientlyrecognized as a significant difference.

[0081] Paper strength (tearing strength)

[0082] Each sheet having a regulated moisture content was examinedaccording to JIS P 8116 (Testing Method for Tearing Strength of Paperand Paperboard).

[0083] Equation for calculation:

Tearing strength=A/S×16

[0084] Tearing strength: (gf)

[0085] A: Reading

[0086] S: Number of torn sheets

[0087] The larger the absolute value of tearing strength, the higher thepaper strength. A difference of 20 gf in tearing strength issufficiently recognized as a significant difference. TABLE 7 Cationiccompound, amine compound, acid Nonionic Deinked salt of amine surfactantpulp LBKP compound, of used in Bulk Tearing Bulk Tearing amphotericcombination (i)/(ii) density strength density strength Example compound(i) (ii) weight ratio (g/cm³) (gf) (g/cm³) (gf) 1 B-1 none — 0.330 4200.377 480 2 B-2 ↑ — 0.328 420 0.376 480 3 B-3 ↑ — 0.325 415 0.374 475 4B-4 ↑ — 0.330 415 0.378 480 5 A-1 ↑ — 0.325 420 0.375 475 6 A-2 ↑ —0.330 420 0.377 480 7 C-1 ↑ — 0.342 430 0.385 485 8 C-2 ↑ — 0.340 4300.383 485 9 C-3 ↑ — 0.338 425 0.383 480 10 C-4 ↑ — 0.335 420 0.379 48011 C-5 ↑ — 0.332 420 0.377 480 12 D-1 ↑ — 0.331 415 0.377 475 13 D-2 ↑ —0.331 415 0.377 475 14 D-3 ↑ — 0.328 420 0.375 475 15 B-1 1 20/80 0.313410 0.349 470 16 B-3 2 30/70 0.308 400 0.342 460 17 B-3 3 50/50 0.309405 0.344 455 18 B-3 4 85/15 0.312 410 0.346 460 19 B-3 5 90/10 0.314410 0.349 465 20 A-1 6 85/15 0.309 400 0.345 460 21 B-4 7 30/70 0.310405 0.345 455 22 B-3 8 20/80 0.308 400 0.341 460 23 C-2 9 65/35 0.324410 0.360 470 24 C-3 10 80/20 0.323 415 0.358 470 25 C-4 11 10/90 0.317415 0.355 465 26 C-5 12 70/30 0.321 410 0.357 465 27 C-5 13 55/45 0.322415 0.357 470 28 C-5 14 20/80 0.319 415 0.356 465 29 D-1 15 15/85 0.314410 0.348 460 30 D-3 16 80/20 0.312 405 0.345 460 31 D-3 17 35/65 0.308400 0.342 455

[0088] TABLE 8 Cationic compound, amine compound, acid salt of aminecompound, or Nonionic Deinked pulp LBKP amphoteric surfactant used inBulk density Tearing strength Bulk density Tearing strength Examplecompound (i) combination (ii) (g/cm³) (gf) (g/cm³) (gf) 32 b-1 none0.366 440 0.405 495 33 b-2 ↑ 0.365 440 0.402 485 34 a-1 ↑ 0.365 4350.404 490 35 a-2 ↑ 0.366 430 0.405 490 36 c-1 ↑ 0.367 435 0.404 495 37c-2 ↑ 0.368 430 0.407 490 38 c-3 ↑ 0.365 425 0.404 490 39 c-4 ↑ 0.365435 0.403 485 40 c-5 ↑ 0.366 430 0.405 490 41 d-1 ↑ 0.364 440 0404 49542 d-2 ↑ 0.363 430 0.406 490 Control (no bulking 0.375 430 0.414 490promoter) Comparative example 1 0.330 280 0.379 345

1. A process for producing a bulky paper, comprising the step of: makingpaper from a pulp feedstock in the presence of a bulking promoter,wherein said bulking promoter is added to the pulp feedstock and evenlyblended with the pulp feedstock in a papermaking process step, and saidbulking promoter comprising a cationic compound represented by formula(a₁) or (b₁):

wherein in formula (a₁) or (b₁), R₁₁ and R₁₂ are the same as ordifferent from each other, and each represents an alkyl, alkenyl orβ-hydroxyalkyl group having 8 to 24 carbon atoms; R₁₃, R₁₄ and R₁₅ arethe same as or different from each other, and each of R₁₃, R₁₄ and R₁₅represents an alkyl group or hydroxyalkyl group having 1 to 8 carbonatoms, benzyl or —(AO)n₁₁—Z₁₁, wherein AO is an oxyalkylene unit having2 or 3 carbon atoms, Z₁₁ represents a hydrogen atom or an acyl group,and n₁₁ is an integer of 1 to 50; R₁₆ represents an alkyl, an alkenyl orβ-hydroxyalkyl group having 8 to 36 carbon atoms; and X⁻ is an anion. 2.The process of claim 1, wherein said bulking promoter in said step ofmaking paper further comprises at least one of the nonionic surfactantsrepresented by (A) to (C): (A): a compound represented by the followingformula (A) R₈₁O(EO)_(m) ₈₁ (PO)_(n) ₈₁ H  (A) wherein R₈₁ is a C6 toC22 straight or branched alkyl or alkenyl group or an alkylaryl grouphaving a C4 to C20 alkyl group; E is an ethylene unit; P is a propyleneunit; m₈₁ and n₈₁ are an average number of added moles, m₈₁ is a numberin the range of 0 to 20 and n₈₁ is a number in the range of 0 to 50; andthe addition form of EO and PO may be any of block and random and theaddition order of EO and PO may not be limited; (B): a compoundrepresented by the following formula (B) R₈₁COO(EO)_(m) ₈₁ (PO)_(n) ₈₁R_(b)  (B) wherein R₈₁, E, P, m₈₁ and n₈₁ are the same as those of theformula (A); and R_(b) is H, an alkyl group, an alkenyl group or analkylaryl group; (C): a nonionic surfactant selected from the following(1) to (3): (1) a nonionic surfactant based on fat, (2) a nonionicsurfactant based on sugar alcohol, and (3) a nonionic surfactant basedon sugar.
 3. The process of claim 1, wherein the blended mixture of thepulp feedstock and said bulking promoter is subjected to a sheet-formingstep.
 4. The process of claim 1, wherein said bulking promoter is addedin an amount of 0.01 to 10 wt % based on the weight of the pulp.
 5. Aprocess for producing a bulky paper, comprising the step of: makingpaper from a pulp feedstock in the presence of a bulking promoter,wherein said bulking promoter is added to the pulp feedstock and evenlyblended with the pulp feedstock in a papermaking process step, and saidbulking promoter comprising a cationic compound represented by formula(a₆) or (b₆):

wherein in formula (a₆) or (b₆), R₆₁ and R₆₃ are the same or differentfrom each other, and each represents an alkyl, alkenyl or β-hydroxyalkylgroup having 7 to 35 carbon atoms; R₆₅ represents a hydrogen atom or analkyl group having 1 to 3 carbon atoms; R₆₂ and R₆₄ are the same ordifferent from each other, and each represents an alkyl group having 1to 3 carbon atoms; and X⁻ is an anion.
 6. The process of claim 5,wherein said bulking promoter in said step of making paper furthercomprises at least one of the nonionic surfactants represented by (A) to(C): (A): a compound represented by the following formula (A)R₈₁O(EO)_(m) ₈₁ (PO)_(n) ₈₁ H  (A) wherein R₈₁ is a C6 to C22 straightor branched alkyl or alkenyl group or an alkylaryl group having a C4 toC20 alkyl group; E is an ethylene unit; P is a propylene unit; m₈₁ andn₈₁ are an average number of added moles, m₈₁ is a number in the rangeof 0 to 20 and n₈₁ is a number in the range of 0 to 50; and the additionform of EO and PO may be any of block and random and the addition orderof EO and PO may not be limited; (B): a compound represented by thefollowing formula (B) R₈₁COO(EO)_(m) ₈₁ (PO)_(n) ₈₁ R_(b)  (B) whereinR₈₁, E, P, m₈₁ and n₈₁ are the same as those of the formula (A); andR_(b) is H, an alkyl group, an alkenyl group or an alkylaryl group; (C):a nonionic surfactant selected from the following (1) to (3): (1) anonionic surfactant based on fat, (2) a nonionic surfactant based onsugar alcohol, and (3) a nonionic surfactant based on sugar.
 7. Theprocess of claim 5, wherein the blended mixture of the pulp feedstockand said bulking promoter is subjected to a sheet-forming step.
 8. Theprocess of claim 5, wherein said bulking promoter is added in an amountof 0.01 to 10 wt % based on the weight of the pulp.